Flutter聊天应用Android端FCM通知失效问题求助

我正在开发一款Flutter聊天应用，需要实现用户收到新消息时的通知功能。该功能在iOS设备上运行正常，但Android设备完全无法生效，请求帮助。

具体问题 #

• 请求通知权限时，Android设备未弹出权限请求弹窗
• 已添加FirebaseMessaging.onMessage监听，但依然收不到通知
• FCM Token获取功能正常，数据库中能看到Android设备的Token，且云函数已通过该Token发送了通知

已实现的代码 #

权限请求与消息监听代码

import 'package:firebase_messaging/firebase_messaging.dart';

class PermissionService {
  Future<void> notification() async {
    await FirebaseMessaging.instance.requestPermission(
      alert: true,
      announcement: false,
      badge: true,
      carPlay: false,
      criticalAlert: false,
      provisional: false,
      sound: true,
    );

    FirebaseMessaging.onMessage.listen((event) {
      print("A new message event was published");
    });

    FirebaseMessaging.onMessageOpenedApp.listen((event) {
      print("A new OpenedAppMessage event was published");
    });
  }
}

FCM Token获取代码

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_messaging/firebase_messaging.dart';

class FCMService {
  final FirebaseAuth _firebaseAuth = FirebaseAuth.instance;

  Future<void> createFcmToken() async {
    final User? user = _firebaseAuth.currentUser;
    final fcmToken = await FirebaseMessaging.instance.getToken();

    if (user != null) {
      await FirebaseFirestore.instance
          .collection("fcm_token")
          .doc(user.uid)
          .set({
        "fcm_token": fcmToken,
        "user_id": user.uid,
      });
    }
  }
}

排查方向及解决方案 #

1. Android 13+权限补充配置

   • Android 13及以上版本需单独申请POST_NOTIFICATIONS权限，Firebase Messaging的requestPermission()默认不包含该权限：
     • 在AndroidManifest.xml中添加权限声明：

       <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
       

     • 使用permission_handler包主动请求权限：

       import 'package:permission_handler/permission_handler.dart';
       
       Future<void> requestAndroidNotificationPermission() async {
         if (await Permission.notification.isDenied) {
           await Permission.notification.request();
         }
       }
       

2. 前台通知渠道创建

   • Android前台消息必须绑定通知渠道才能显示，应用初始化时添加以下代码：

     import 'package:flutter_local_notifications/flutter_local_notifications.dart';
     
     final FlutterLocalNotificationsPlugin _notificationsPlugin = FlutterLocalNotificationsPlugin();
     
     Future<void> initializeLocalNotifications() async {
       const AndroidInitializationSettings initializationSettingsAndroid =
           AndroidInitializationSettings('@mipmap/ic_launcher');
       const InitializationSettings initializationSettings =
           InitializationSettings(android: initializationSettingsAndroid);
       await _notificationsPlugin.initialize(initializationSettings);
     
       // 创建高优先级通知渠道
       const AndroidNotificationChannel channel = AndroidNotificationChannel(
         'chat_notification_channel',
         '聊天通知',
         description: '接收新消息通知',
         importance: Importance.max,
       );
       await _notificationsPlugin.resolvePlatformSpecificImplementation<AndroidFlutterLocalNotificationsPlugin>()?.createNotificationChannel(channel);
     }
     

   • 修改onMessage监听，手动触发本地通知：

     FirebaseMessaging.onMessage.listen((RemoteMessage message) {
       RemoteNotification? notification = message.notification;
       AndroidNotification? android = message.notification?.android;
     
       if (notification != null && android != null) {
         _notificationsPlugin.show(
           notification.hashCode,
           notification.title,
           notification.body,
           NotificationDetails(
             android: AndroidNotificationDetails(
               'chat_notification_channel',
               '聊天通知',
               channelDescription: '接收新消息通知',
               icon: android.smallIcon,
             ),
           ),
         );
       }
     });
     

3. 后台消息处理配置

   • 创建FirebaseMessagingService子类处理后台消息（需在AndroidManifest.xml注册）：

     class MyFirebaseMessagingService : FirebaseMessagingService() {
         override fun onMessageReceived(remoteMessage: RemoteMessage) {
             super.onMessageReceived(remoteMessage)
             // 此处可调用本地通知展示后台消息
         }
     }
     

4. 云函数消息格式校验

   • 确保云函数发送的消息包含notification字段（前台展示）和android.priority: 'high'配置，示例：

     const message = {
       token: fcmToken,
       notification: {
         title: '新消息',
         body: '您收到一条新消息'
       },
       data: {
         chatId: 'xxx'
       },
       android: {
         priority: 'high'
       }
     };
     

内容的提问来源于stack exchange，提问作者Juliettead